D-STAR Discussion on QRZ.COM

As usual with many topics, there is a lively debate about D-STAR on qrz.com. Unfortunately, there seems to be a bunch of folks that hang out on qrz just to be negative on any new ideas. Here’s the easy-to-read summary of the qrz.com discussion. (I am saving you the trouble of wading through all the QRM.)

VE7TKO (a vocal proponent of D-STAR) starts the discussion with:

D-STAR is probably the greatest advancement ever seen in ham radio to date. D-STAR stands for “Digital Smart Technologies for Amateur Radio”.

Then the opposition comes screaming in:

Objection Number 1: D-STAR is proprietary, not an open standard.

Reality: Not True…D-STAR is an open standard. The system has been developed in collaboration with and is owned by JARL (Japan Amateur Radio League).

Objection Number 2: The commercial / land mobile standard APCO-25 is the way to go, not D-STAR.
Reality: APCO-25 was developed for police/fire/public safety radio. It may be applicable to ham radio use, but D-STAR was designed specifically for amateur use. Amateur radio has a history of adopting commercial standards but it is not clear that APCO-25 will win out over D-STAR.

Objection Number 3: D-STAR isn’t the essence of ham radio, more like a cellphone system.
Reality: It depends on how you define the essence of ham radio. I see it as applying new technology in interesting and useful ways. An open mind is a wonderful thing. :-)

Objection Number 4: The Internet is bad for ham radio, so connecting the Internet to ham radio is even worse.
Reality: Changes in technology outside of ham radio will continue to affect ham radio. Example: There was a time when we had no computers, now they are common. Ham radio was obviously affected by this new technology (for the better, I argue). To expect new, relevant technologies to not influence ham radio is kind of silly.

Objection Number 5: This system tracks your position for everyone to see. Sounds like “Big Brother” to me.
Reality: Ever heard of APRS? Don’t turn on the feature and you’ll be fine.

Objection Number 6: Only ICOM has D-STAR radios, so it is a one vendor solution.
Reality: Good point. If D-STAR is going to get widely adopted other manufacturers must join in. Kenwood is rumored to be introducing a D-STAR radio.

Objection Number 7: I don’t see the clear, compelling benefit to using D-STAR.
Reality: Another good point. It is still fuzzy how the average Joe Ham will benefit from D-STAR. Meanwhile, some of the technie hams are experimenting with new D-STAR systems.

Objection Number 8: D-STAR radios cost more than analog FM radios.
Reality: Yes, for now anyway. The price will have to come down for it to be successful, which is common for new technologies.

For more information on D-STAR see http://www.icomamerica.com/amateur/dstar/dstar2.asp

3 thoughts on “D-STAR Discussion on QRZ.COM

  1. If you try to talk through an analog repeater, in digital mode, it will not work. The repeater must be able to receive a digital carrier and re-broadcast a digital carrier.

    Since a digital carrier is different than an analog carrier, a non-digital radio can not re-broadcast the digital carrier. It’s not just digital data, it’s an actual digital signal. If you try to transmit, in digital mode, into an analog repeater, all the analog radios on the repeater will simply hear white noise and a digital radio listening will hear nothing. The digital radio will see activity on the signal strength meter, as would be normal when there is analog activity on the frequency.

    _____________________________

    Kevin McClinton, W7JRL
    Amateur Technical Trainer

    ICOM America, Inc.
    2380 116th Ave. NE
    Bellevue, WA 98004
    Ph. (425) 454-7619
    Fax (425) 637-8417
    http://www.icomamerica.com

  2. Here is what the ex DSTAR expert says.

    The above comments are not out of context and do not confuse the issue they bring clarity and truth to the issue. The above comments where on the ICOM website before they where removed. DSTAR will require that the all the analog repeaters be replaced to be able to use DSTAR.

    DSTAR also means that we can not us any hand me down used commercial anolog repeaters in the Amatuer Bands. DSTAR will also obselete all of the existing anolog radios we already own. Some of us do not want to replace or equipment.

    Added after 9 minutes:

    This is what the EX ICOM DSTAR GUY SAYS.

    The answer is, NO it will not work.

    The reason is simple, the modulation scheme is not compatible, nor is the repeaters circuitry.

    In a typical analog repeater, an FM demodulator is used to demodulate the FM signal, effectively “decoding” the voice signal imposed upon the carrier, by way of Frequency Modulation. The analog repeater then takes the analog audio, and passes it to the repeaters transmitter, where it is “re-encoded”, by the FM modulator and sent over the air.

    In a D-STAR repeater, an IQ demodulator is used, to “decode” the data imposed upon the carrier, by way of Gaussian Minimum Shift Keying. Once the digital signal, effectively ones and zeros, is extracted, it is buffered and regenerated. The regenerated signal is sent to the transmitter where it is “re-encoded” and sent out over the air.

    As you can see, the operation is similar, up to the point where the signal is received, by the repeater, but after that, the process, and type of signal (one being audio and the other be data ones and zeros) is very different.

    Any type of digital system, that uses tones, or audio, to represent data, can be passed through an analog repeater, because that’s what analog repeaters pass, Audio. Not all analog repeaters will pass that digital signal well, since there can be level and fidelity issues, but it should work. That’s also why D-STAR a “true” digital system will not go through any analog repeater.

    _____________________________

    Matthew F. Yellen K7DN
    Systems Engineer

  3. Ham Radio needs to stay INDEPENDENT of the internet and ALL commercial systems if it to remain a truely reliable Backup global communications media.

    Point to Point communications is Essential.